This invention relates generally to a cushioning conversion machine which converts paper stock into cushioning material, and more particularly, to a cushioning conversion machine an outlet conveyor and an assembly for preventing accumulating pads from nesting becoming damaged or causing jamming of the cushioning conversion machine.
In the process of shipping an item from one location to another, a protective packaging material is typically placed in the shipping container to fill any voids and or to cushion the item during the shipping process. Some commonly used protective packaging materials are plastic foam peanuts and plastic bubble pack. While these conventional plastic materials seem to perform adequately as cushioning products, they are not without disadvantages. Perhaps the most serious drawback of plastic bubble wrap and or plastic foam peanuts is their effect on our environment. Quite simply, these plastic packaging materials are not biodegradable and thus they cannot avoid further multiplying our planet""s already critical waste disposal problems. The non-biodegradability of these packaging materials has become increasingly important in light of many industries adopting more progressive policies in terms of environmental responsibility.
These and other disadvantages of conventional plastic packaging materials have made paper protective packaging material a very popular alternative. Paper is biodegradable, recyclable and renewable; making it an environmentally responsible choice for conscientious companies.
While paper in sheet form could possibly be used as a protective packaging material, it is usually preferable to convert the sheets of paper into a low density cushioning product. This conversion may be accomplished by a cushioning conversion machine, such as those: disclosed in U.S. Pat. Nos. 4,026,198; 4,085,662; 4,109,040; 4,237,776; 4,557,716; 4,650,456; 4,717,613; 4,750,896; and 4,968,291. (These patents are all assigned to the assignee of the present invention and their entire disclosures are hereby incorporated by reference.) Such a cushioning conversion machine converts sheet-like stock material, such as paper in multi-ply form, into low density cushioning pads or dunnage.
A cushioning conversion machine, such as those disclosed in the above-identified patents, may include a stock supply assembly, a forming assembly, a gear assembly, and a cutting assembly, all of which are mounted on the machine""s frame. During operation of such a cushioning conversion machine, the stock supply assembly supplies the stock material to the forming assembly. The forming assembly causes inward rolling of the lateral edges of the sheet-like stock material to form a continuous strip having lateral pillow-like portions and a thin central band. The gear assembly, powered by a feed motor, pulls the stock material through the machine and also coins the central band of the continuous strip to form a coined strip. The coined strip travels downstream to the cutting assembly which cuts the coined strip into pads of a desired length.
Typically, the cut pad is transferred downstream to a transitional zone, such as a table, a conveyor, a bin, etc., and is thereafter removed from the transitional zone and inserted within a container for cushioning purposes. In the past, the transitional zone has been positioned beneath the cutting assembly whereby gravity caused the pad to fall towards the transitional zone, or, in other words, away from the cutting assembly. Additionally or alternatively, the approaching coined strip would urge the cut pad in this direction.
The practice of depending upon the force of gravity and or the urging of the approaching strip for pad-transferring purposes has, for the most part, been very successful. Nevertheless, applicant appreciated that in certain circumstances (such as high constant volume cushioning situations), pad-transfer problems sometimes, albeit very rarely, occurred. For example, because of the lightweight nature of the pad, one would occasionally fail to travel downstream to the transitional zone. While, in most instances, the approaching pads would eradicate this failure by pushing the xe2x80x9cstalledxe2x80x9d pad downstream, periodically the approaching pads would instead xe2x80x9cshinglexe2x80x9d (ie., the pads would stack one on top of the other in a shingle-like arrangement). Such shingling (although itself uncommon) would usually result in the xe2x80x9cjammingxe2x80x9d of the cushioning conversion machine and this jamming would almost always translate into machine downtime.
Further, problems could arise from the accumulation of a large number of pads in the transitional zone, such as on a conveyor. While the use of a conveyor, generally works well in conveying formed pads away from the cushioning conversion machine, if the conveyor were to become filled with pads, the pads would tend to nest or shingle resulting in the difficult removal of the pads from the conveyor and possible damage to the pads.
The present invention provides a cushioning conversion system including a cushioning conversion machine and a conveyor system which conveys pads away from the machine while preventing pads from becoming nested or forced together. The conveyor system includes a series of stop gates which permit a pad to pass by when there is sufficient space for the pad on the conveyor downstream of the stop gate and which stops the progress of the pad along the conveyor when there is insufficient space for the pad. Each stop gate is preferably controlled by an associated sensor located downstream of the gate. A sensor may also be used to determine and communicate to the cushioning conversion machine that there is insufficient space on the conveyor for a new pad, whereupon the machine can discontinue its production of pads until space is available thereby decreasing the potential for jams in the machine.
In accordance with one aspect of the invention, a cushioning conversion system includes a cushioning conversion machine which converts stock paper into a plurality of cut pads, and a conveyor system positioned to receive pads produced by the cushioning conversion machine and including a conveyor which conveys the pads away from the machine and at least one moveable gate having an open position allowing a pad to pass therethrough and a closed position for stopping progress of a pad along the conveyor when there is insufficient space on the conveyor downstream of the gate to permit a pad to progress substantially through the gate.
In accordance with a further aspect of the invention, a cushioning conversion system includes a cushioning conversion machine which converts stock paper into a plurality of cut pads, and a conveyor system positioned to receive pads produced by the cushioning conversion machine and including a conveyor which conveys the pads away from the machine and at least one moveable gate having an open position allowing a pad to pass therethrough and a closed position for stopping progress of a pad along the conveyor.
In accordance with a still further aspect of the invention, a cushioning conversion system includes a reversible conveyor system, and a cushioning conversion machine located at each end of the reversible conveyor system, each machine for selectively converting stock paper into a plurality of cut pads and depositing the pads on the conveyor system when active, the reversible conveyor system including a conveyor which conveys the pads away from the active machine and at least one moveable gate having an open position allowing a pad to pass therethrough and a closed position for stopping progress of a pad along the conveyor.
In general, the invention comprises the foregoing and other features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrated embodiment of the invention, this being indicative, however, of but one of the various ways in which the principles of the invention may be employed.